Investigating the mechanism of cornel iridoid glycosides on type 2 diabetes mellitus using serum and urine metabolites in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Cornel iridoid glycosides (CIG) are extracted from Corni fructus, a herbal medicine used in traditional Chinese medicine to treat diabetes. However, the antidiabetic effects of CIG and the underlying metabolic mechanisms require further exploration. AIM OF THE STUDY: This study aimed to assess the antidiabetic effects and metabolic mechanism of CIG by performing metabolomic analyses of serum and urine samples of rats. MATERIALS AND METHODS: A rat model of type 2 diabetes mellitus (T2DM) was established by administering a low dose of streptozotocin (30 mg/kg) intraperitoneally after 4 weeks of feeding a high-fat diet. The model was evaluated based on several parameters, including fasting blood glucose (FBG), random blood glucose (RBG), urine volume, liver index, body weight, histopathological sections, and serum biochemical parameters. Subsequently, serum and urine metabolomics were analyzed using ultra-high-pressure liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap-MS). Data were analyzed using unsupervised principal component analysis (PCA) and supervised orthogonal partial least squares discriminant analysis (OPLS-DA). Differential metabolites were examined by the Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways to explore the underlying mechanisms. RESULTS: After 4 weeks of treatment with different doses of CIG, varying degrees of antidiabetic effects were observed, along with reduced liver and pancreatic injury, and improved oxidative stress levels. Compared with the T2DM group, 19 and 23 differential metabolites were detected in the serum and urine of the CIG treatment group, respectively. The key metabolites involved in pathway regulation include taurine, chenodeoxycholic acid, glycocholic acid, and L-tyrosine in the serum and glycine, hippuric acid, phenylacetylglycine, citric acid, and D-glucuronic acid in the urine, which are related to lipid, amino acid, energy, and carbohydrate metabolism. CONCLUSIONS: This study confirmed the antidiabetic effects of CIG and revealed that CIG effectively controlled metabolic disorders in T2DM rats. This seems to be meaningful for the clinical application of CIG, and can benefit further studies on CIG mechanism.

Anti-inflammatory and urease inhibitory iridoid glycosides from Nyctanthes arbor-tristis Linn.

ETHNOPHARMACOLOGICAL RELEVANCE: Nyctanthes arbor-tristis Linn. has been used by Ayruvedic physicians for the cure of different diseases including ulcers, gastric and inflammatory diseases. AIM OF THE STUDY: To isolate and identify compounds from this source and investigate their therapeutic potential for the treatment of gastric ulcer and related disorders. MATERIAL AND METHODS: The ethanol extract of fresh aerial parts of N. arbor-tristis was used in the present studies which was subjected to a bio-assay guided fractionation followed by chromatographic separations. The structures of pure compounds were elucidated using various spectroscopic techniques. The inhibition of urease enzyme was evaluated by weatherburn indophenol method. Molecular docking studies were determined by using Molecular Operating Environment (MOE) version 2020.0901 version. The intracellular ROS production from phagocytes was determined by chemiluminescence assay and NO generation was detected by Griess method. The proinflammatory cytokine TNF-α was quantified by ELISA. Cytotoxic activity was assessed by MTT assay. RESULTS: One previously undescribed iridoid glycoside arborside F (1) and four known iridoid glycosides arborside A (2), arborside C (3), loganin (4) and 7-O-trans-cinnamoyl-6ß-hydroxyloganin (5) were isolated and characterized in the present studies and their urease inhibitory activity was determined. Among these, 2 and 5 showed strong urease inhibition (IC50 = 12.1 ± 1.74 and 14.1 ± 0.59 µM respectively) (standard acetohydroxamic acid IC50 = 20.3 ± 0.42 µM), whereas rest of compounds showed moderate to low inhibition. Kinetic studies revealed that compounds 2 and 5 possess competitive type of inhibition. Molecular docking showed polar and non-polar interactions of compounds 2 and 5 with urease enzyme residues. Compounds 2 and 3 showed inhibition of ROS from whole blood (IC50 = 1.6 ± 0.3 and 2.5 ± 0.09 µg/mL respectively) and PMNs (IC50 = 1.5 ± 0.03 and 1.4 ± 0.0 µg/mL respectively). Compound 2 significantly inhibited nitric oxide and proinflammatory cytokine TNF-α (IC50 = 18.2 ± 3.0 and 73.8 ± 6.6 µg/mL respectively). Compounds 1, 4 and 5 were inactive on ROS. All isolated compounds were non-toxic on normal mouse fibroblasts (NIH-3T3) cells. CONCLUSIONS: The ethno pharmacological repute of N. arbor-tristis in treating gastric and anti-inflammatory ailments is supported by present studies which resulted in isolation of a potent urease inhibitory and anti-inflammatory agent arborside A (2) a potential anti-ulcer and anti-inflammatory drug lead.

Geniposide from Gardeniae Fructus exerts antipyretic effect in febrile rats through modulating the TLR4/NF-κB signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: The desiccative ripe fruits of Gardenia (Gardenia jasminoides Ellis) (called Zhizi in China) are known with cold character and the effects of reducing fire except vexed, clearing away heat evil, and cooling blood and eliminating stasis. Zhizi is often clinical formulated to treat various types of fever. Fever is a sign of inflammation and, geniposide from Zhizi has been proved with anti-inflammatory in various inflammatory models. AIM OF STUDY: The aim of this study was to investigate the antipyretic role of geniposide with three classical inflammatory fever models and explore the underlying mechanisms. MATERIALS AND METHODS: Water extract (WE), high polar part (HP), iridoid glycoside part (IG), and gardenia yellow pigment part (GYP) from Gardeniae Fructus (GF) were obtained from Zhizi. The antipyretic activities of these composes were tested with dry yeast induced fever rats. Geniposide was further purified from IG and the antipyretic activity was evaluated by gavage, intraperitoneal injection, and caudal intravenous injection to rats of fever induced by dry yeast, lipopolysaccharide (LPS), and 2, 4-dinitrophenol (DNP) in rats. Then, the mechanism of geniposide by intragastric administration was studied. The contents of thermoregulatory mediators and inflammatory factors relating to TLR4/NF-κB pathway in serum were determined by ELISA and Western blot, and the pathological changes of the hypothalamus were observed by HE staining. RESULTS: The temperature was decreased by geniposide in the three fever model rats. Geniposide can not only inhibit the increase of inflammatory factors in serum but also protect the hypothalamus from fever pathological damage in the three fever models. Western blot showed that geniposide could inhibit the TLR4/NF-κB pathway. CONCLUSION: Geniposide exerts antipyretic effect in febrile rats through modulating the TLR4/NF-κB signaling pathway.

Six new iridoid glycosides from the whole plants of Hedyotis diffusa.

Six new iridoid glycosides were isolated from the ethyl acetate fraction of the whole plants of Hedyotis diffusa Willd. They were identified as E-6-O-p-methoxycinnamoyl-10-O-acetyl scandoside acid methyl ester (1), Z-6-O-p-methoxycinnamoyl-10-O-acetyl scandoside acid methyl ester (2), E-6-O-caffeoyl scandoside methyl ester (3), E-6-O-p-coumaroyl-6'-O-acetyl scandoside methyl ester (4), Z-6-O-p-coumaroyl-6'-O-acetyl scandoside methyl ester (5), and E-6-O-p-coumaroyl-4'-O-acetyl scandoside methyl ester (6). The structures of them were elucidated based on unambiguous spectroscopic data (UV, IR, HRESIMS, and NMR). They were screened for anti-inflammatory effect, antioxidant effect, antitumor effect, and neuroprotective effect and did not show potent activities.

Secoiridoid glycosides from the fruits of Ligustrum lucidum and their in vitro anti-inflammatory activity.

Seven new secoiridoid glycosides (1-7), together with a known analogue (8), were isolated from the fruits of Ligustrum lucidum. Their structures with absolute configurations were determined by HR-ESI-MS, 1D and 2D NMR, and electronic circular dichroism (ECD) spectroscopic analysis, as well as biogenetic consideration. Compounds 1 and 2 are the first examples of secoiridoid glycoside dimers featuring a rare rearranged oleoside-type secoiridoid moiety, and compounds 3-7 represent a new class of oleoside-type secoiridoid glycosides with unusual stereochemistry at C-1 position. A plausible biosynthetic pathway for this group of unusual secoiridoid glycosides was also proposed herein. In addition, the isolates were evaluated for their in vitro anti-inflammatory activity, and all tested compounds exhibited modest inhibitory effects against nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW264.7 macrophages.

Seco-iridoid glycosides from the Gentiana olivieri Griseb and their bioactivities.

The ethanol extract of the Gentiana olivieri Griseb plant was subjected to an investigation to ascertain the presence of its iridoid constituents. By means of HPLC and TLC monitoring, a total of thirteen previously unreported seco-iridoid glucosides olivierisecoside A-M, as well as seven known seco-iridoid glycosides and one known iridoid glycoside were isolated. Their structures were elucidated by a comprehensive spectroscopic data analysis and ECD calculations. The absolute configuration of olivierisecoside D was further confirmed through single-crystal X-ray diffraction analysis. All the identified compounds were characterized as aromatic conjugated seco-iridoid glucosides, with olivierisecoside F-I representing a particularly rare subtype known as the morroniside type seco-iridoids. In vitro testing of the isolated compounds revealed their potential anti-inflammatory and hepatoprotective effects. The results showed olivieroside B and 6'-gentisoyl-8-epi-kingiside have good anti-inflammatory activities in LPS induced RAW264.7 cells. Additionally, olivierisecoside M exhibited some improvements in PA-induced L02 and HepG2 cells damage, known compound loganin showed slight hepatoprotective effect in PA-induced HepG2 cells damage.

Five New Glycoside Constituents from the Roots of Gentiana crassicaulis Duthie ex Burk.

Three undescribed glycoside constituents, macrophyllosides E-G and a pair of iridoid glycosides genticrasides A/B, together with eleven known glycoside compounds were isolated from the roots of Gentiana crassicaulis Duthie ex Burk. Their structures were identified by means of spectra analysis and data comparison with previous literatures. Interestingly, the glucose moieties in macrophylloside E and F possess free anomeric hydroxy groups. Genticrasides A/B, identified as a pair of iridoid originated lactones, have not been reported from Gentianaceae family up to now. The anti-inflammatory effects of selected compounds were also evaluated through the nitric oxide (NO) production inhibition in lipopolysaccharides (LPS)-induced RAW264.7 macrophage cells. In which, macrophyllosides G and D showed NO inhibitory activities with rates of 76.14±4.02 % and 52.44±8.29 % at 100 µg/mL.

Anti-inflammatory iridoid glycosides from Paederia scandens (Lour.) Merrill.

Eight previously undescribed iridoid glycosides together with 20 known congeners were isolated from the aerial parts of Paederia scandens (Lour.) Merrill (Rubiaceae). Their structures incorporating absolute configurations were elucidated based on the comprehensive analyses of NMR data, HR-ESI-MS spectrometry, and ECD data. The potential anti-inflammatory activities of the isolated iridoids were evaluated in lipopolysaccharide-stimulated RAW 264.7 macrophages. Compound 6 significantly inhibited the production of nitric oxide with an IC50 value of 15.30 µM. The results of immunoblotting, qPCR, and immunofluorescence staining assays revealed that compound 6 exhibited anti-inflammatory activity by suppressing nuclear translocation of NF-κB and reducing the expression of COX-2, iNOS, IL-1ß, and IL-6. These results provide a basis for further development and utilization of P. scandens as a natural source of potential anti-inflammatory agents.

The total iridoid glycoside extract of Lamiophlomis rotata Kudo induces M2 macrophage polarization to accelerate wound healing by RAS/ p38 MAPK/NF-κB pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Lamiophlomis rotata (Benth.) Kudo (L. rotata), a Tibetan medicinal plant, is used to treat "yellow-water diseases", such as skin disease, jaundice and rheumatism. Our previous study showed that the iridoid glycoside extract of L. rotata (IGLR) is the major constituent of skin wound healing. However, the role of IGLR in the biological process of trauma repair and the probable mechanism of the action remain largely unknown. AIM OF THE STUDY: To investigate the role of IGLR in the biological process of trauma repair and the probable mechanism of the action. MATERIALS AND METHODS: The role of IGLR in wound healing was investigated by overall skin wound in mice with Hematoxylin and Eosin (H&E) and Masson trichrome staining. The anti-inflammatory, angiogenesis-promoting and fibril formation effects of IGLR were visualized in wound skin tissue by immunofluorescence staining, and the proinflammatory factors and growth factors were assayed by real-time polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Macrophages, dermal fibroblasts, and endothelial cells were cultured to measure the direct/indirect interaction effects of IGLR on the proliferation and migration of cells, and flow cytometry was employed to assess the role of IGLR on macrophage phenotype. Network pharmacology combined with Western blot experiments were conducted to explore possible mechanisms of the actions. RESULTS: IGLR increased the expression of CD206 (M2 markers) through the RAS/p38 MAPK/NF-κB signaling pathway during wound injury in vivo and in vitro. IGLR suppressed the inflammatory cytokines iNOS, IL-1ß and TNF-α in the early stage of wound healing. During the proliferation step of wound repair, IGLR promoted angiogenesis and fibril formation by increasing the expression of VEGF, CD31, TGF-ß and α-SMA in wound tissue, and similar results were verified by RT-PCR and ELISA. In a paracrine mechanism, the extract promoted the proliferation of dermal fibroblasts, and endothelial cells were founded by the conditioned medium (CM). CONCLUSION: IGLR induced M2 macrophage polarization in the early stage of wound healing; in turn, IGLR played a key role in the transition from inflammation to cell proliferation during the biological process of wound healing.

Hastatoside attenuatescarbon tetrachloride-induced liver fibrosis by targeting glycogen synthase kinase-3ß.

BACKGROUND: Hastatoside is an iridoid glycoside extracted from the herb, Verbena officinalis, that exerts various pharmacological effects, including anti-inflammatory, sleep-promoting, and analgesic effects. However, only a few studies have reported the efficacy of hastatoside in liver fibrosis. Liver fibrosis is a pathophysiological process, and its persistence can seriously affect the quality of life and well-being of the patients. HYPOTHESIS/PURPOSE: This study aimed to investigate the role of hastatoside on liver fibrosis and its possible underlying mechanisms. METHODS: C57BL/6 J mice with carbon tetrachloride (CCl4)-induced hepatic fibrosis were used as the in vivo models. Histological features of the liver were observed using Masson's trichrome and hematoxylin-eosin staining. Alanine aminotransferase and aspartate aminotransferase levels and the hepatic fibrosis indices (type 3 procollagen, laminin, and hyaluronic acid) were measured using corresponding assay kits. LX-2 human hepatic stellate cells (HSCs) stimulated with the transforming growth factor ß1 were used as the vitro models. Transfection of the glycogen synthase kinase (GSK)-3ß small interfering RNA (siRNA) and ß-catenin plasmids was also performed in vitro. Protein levels of GSK-3ß, phospho-GSK-3ß (Ser 9), α-smooth muscle actin, collagen type I alpha 1, c-Myc, cyclin D1, and ß-catenin were determined via western blotting. Moreover, the p-GSK-3ß:GSK-3ß ratio was calculated to determine the GSK-3ß activity. RESULTS: Hastatoside prevented CCl4-induced liver injury and histological damage. It inhibited the upregulation of α-SMA and Col1α1 levels in a CCl4-induced mouse hepatic fibrosis model. In vitro, hastatoside inhibited the proliferation and activation of HSCs by decreasing the expression levels of cyclin D1 and c-Myc and the proportion of LX-2 cells activated in the G0/G1 phase. Molecular docking results showed that hastatoside bound to GSK-3ß. Hastatoside significantly increased the GSK-3ß activity and inhibited the downstream effector expression of ß-catenin. CONCLUSION: These findings suggest that hastatoside can bind to GSK-3ß and promote its activity, while inhibiting the GSK-3ß downstream effector expression of ß-catenin, thereby inhibiting the activation and proliferation of HSCs, which further prevents the development of liver fibrosis. These results provide innovative insights into the underlying liver fibrosis. Moreover, hastatoside is a potential anti-fibrosis monomer that can potentially be used for the treatment of liver fibrosis.

Four undescribed iridoid glycosides with antidiabetic activity from fruits of Cornus officinalis Sieb. Et Zucc.

Four novel iridoid glycosides neocornuside E-H (1-4), together with nine known ones (5-13), were isolated from fruits of Cornus officinalis. Their chemical structures were determined on the basis of spectroscopic analyses and comparing of the literature data. All of the isolated compounds were evaluated for their antidiabetic activity in insulin resistant HepG2 cells. Compounds 2, 4, 5, 8, and 12 exhibited antidiabetic activities with EC50 values of 40.12, 2.54, 70.43, 15.31, and 4.86 µM, respectively. Flow Sight cytometry analysis indicated that compounds 2, 4, 5, 8, and 12 improved the ability of 2-NBDG uptake of insulin-induced HepG2 cells.

Two unusual novel iridoid glycosides from Cornus officinalis fruit and their biological activities.

Two unusual novel iridoid glycosides, cornsecoside A (1) and cornsecoside B (2), were isolated from a 40% ethanol elution fraction of a 50% ethanol extract of Cornus officinalis fruit. Their structures were determined by spectroscopic data analysis combined with hydrolysis and ECD spectroscopy. In addition, compounds 1 and 2 exhibited cytotoxic activity against Bel-7402 cells with IC50 values of 8.12 and 9.31 µM, and were neuroprotective against H2O2-induced SH-SY5Y cell injure at a concentration of 10 µM.

Minor iridoid glycosides from the fruits of Cornus officinalis Sieb. et Zucc. and their anti-diabetic bioactivities.

Fifteen previously undescribed minor iridoid glycosides, including four monomers and eleven dimers, were isolated from the fruits of Cornus officinalis Sieb. et Zucc. Their chemical structures were determined on the basis of spectroscopic data and chemical evidence. All of the isolated compounds were evaluated for their effects of the glucose consumption on the insulin resistant HepG2 cells, and four compounds, named cornuofficinalisides F, H, L, and O, increased the glucose consumption significantly at 10 µM, the EC50 values of them were determined to be 0.898, 1.625, 0.923, and 8.589 µM, respectively. Moreover, the four compounds could improve the ability of glucose uptake significantly in insulin resistant HepG2 cells.

Iridoid Glycosides and Flavonoids Isolated from the Twigs and Leaves of Callicarpa nudiflora and Their Anti-Inflammatory Activities.

A new iridoid glycoside, named 6'-O-trans-feruloyl-8-epiloganic acid, together with fifteen known compounds were isolated from the twigs and leaves of Callicarpa nudiflora, a traditional Chinese medicine to treat inflammatory-related diseases. Their structures were identified by comprehensive spectroscopic analysis and comparison with reported data. Bioassay results revealed that twelve of the isolates could obviously inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 cell lines with IC50 values from 0.64 to 38.72 µM. Among them, compounds 1 (3.27 µM), 6 (5.23 µM), 13 (1.56 µM) and 14 (0.64 µM) exhibited significantly higher activities than that of the positive control (27.13 µM). Additionally, it was supposed that the presence of the carboxy group at the C-4 position of iridoid glycosides and glycosylation at C-3 position of flavonoids might impact their inhibitory activities against NO production.

Cornin protects against cerebral ischemia/reperfusion injury by preventing autophagy via the PI3K/Akt/mTOR pathway.

BACKGROUND: Ischemia stroke is the leading cause of disability, which is a consequence of vascular occlusion. The purpose of this study is to investigate the effect of cornin which is isolated from the fruit of Verbena officinalis L, against astrocytes autophagy induced by cerebral ischemia/reperfusion (CI/R) injury in vitro and in vivo and its potential mechanism. METHODS: Cornin at dose of 2.5, 5 and 10 mg/kg were intravenously injected to MCAO rats at 15 min after reperfusion. The infarction volume, blood-brain barrier (BBB), neurological severity score (mNSS), and autophagy related protein were used to evaluated the protective effects and potential mechanism of cornin in autophagy with or without phosphoinositide-3 kinase (PI3K)inhibitor LY294002 and mammalian target of rapamycin (mTOR) small interfering RNA (siRNA) at 24 h after CI/R injury. The potential protective effects and mechanism of cornin at concention of 10 ~ 1000 nM were also evaluated in oxygen glucose deprivation/reperfusion (OGD/R) in U87 cells. RESULTS: The results suggest that cornin at dose of 5 or 10 mg/kg significantly reduce the cerebral infarction volume and blood-brain barrier (BBB) leakage, and improve neurological recovery in MCAO rats. Cleaved caspase-3 and Bax levels were significantly decreased, while B-cell lymphoma-2 (Bcl-2) and the apoptosis regulator ratio (Bcl-2/Bax) were markedly increased when treated with 2.5-10 mg/kg cornin. The obvious decreased expressions of glial fibrillary acidic protein (GFAP), myosin-like BCL2 interacting protein (Beclin-1) and microtubule-associated protein light chain 3 II (LC3-II) and increased of neuronal nuclei (NeuN), sequestosome-1 (p62), phosphorylated mTOR (p-mTOR), and phosphorylated Akt (p-Akt) were observed in MCAO rats treated with 10 mg/kg cornin, which was counteracted by LY294002. The expression of autophagy-related proteins with or without LY294002 and mTOR siRNA presented the similar results as in vitro in OGD/R in U87 cells. CONCLUSIONS: These results indicate that cornin improved neurological recovery after cerebral ischemia injury by preventing astrocytes autophagy induced by CI/R via the PI3K/Akt/mTOR signaling pathway.

Monotropein Protects against Inflammatory Bone Loss and Suppresses Osteoclast Formation and Bone Resorption by Inhibiting NFATc1 via NF-κB and Akt/GSK-3ß Pathway.

Monotropein (Mon) is a kind of iridoid glycoside plant secondary metabolite primarily present in some edible and medicinal plants. The aim of this study was to investigate the effect of Mon on lipopolysaccharide (LPS)-induced inflammatory bone loss in mice and osteoclasts (OCs) derived from bone marrow-derived macrophages (BMMs), and explore the mechanisms underlying the effect of Mon on LPS-induced osteoclastogenesis. It was found that Mon markedly attenuated deterioration of the bone micro-architecture, enhanced tissue mineral content (TMC) and bone volume/total volume (BV/TV), reduced structure model index (SMI) and trabecular separation/spacing (Tb.Sp) in the bone tissue and decreased the activities of tartrate resistant acid phosphatase-5b (TRACP-5b), receptor activator NF-κB (RANK), and receptor activator NF-κB ligand (RANKL) as well as the serum levels of interleukin 6 (IL-6) and interleukin 1ß (IL-1ß) in LPS-treated mice. In addition, Mon treatment reduced the number of TRAP positive OCs in the bone tissue of LPS-treated mice and also exerted a stronger inhibitory effect on formation, differentiation, and F-actin ring construction of OCs derived from BMMs. Mon significantly inhibited the expression of the nuclear factor of activated T-cells c1 (NFATc1) and the immediate early gene (C-Fos) and nuclear translocation of NFATc1 in LPS-treated OCs, thereby inhibiting the expression of matrix metalloproteinase-9 (MMP-9), cathepsin K (CtsK), and TRAP. Mon significantly inhibited the expression of TRAF6, phosphorylation of P65, and degradation of IKBα, thus inhibiting the activation of NF-κB pathway in LPS-induced inflammatory mice and OCs derived from BMMs, and also inhibited LPS-induced phosphorylation of protein kinase B (Akt) and Glycogen synthase kinase 3ß (GSK-3ß) in OCs derived from BMMs. In conclusion, these results suggested that Mon could effectively inhibit osteoclastogenesis both in vitro and in vivo and therefore may prove to be potential option for prevention and treatment of osteoclastic bone resorption-related diseases.

Cornel Iridoid Glycoside Alleviates Microglia-Mediated Inflammatory Response via the NLRP3/Calpain Pathway.

Vascular dementia (VaD) is associated with cerebral hypoperfusion, which results in long-term cognitive impairment and memory loss. Cornel iridoid glycoside (CIG) is the major active constituent isolated from the ripe fruit of Cornus officinalis. Previous studies have shown that CIG enhances neurological function in VaD rats. In the present research, we attempted to clarify the molecular processes underlying the role of CIG in neuroinflammation in VaD. We created a chronic cerebral ischemia rat model by ligation of the bilateral common carotid arteries (2VO) and then treated rats with different concentrations of CIG. Comprehensive analyses revealed that CIG ameliorated myelin integrity and neuronal loss. Furthermore, we also found that CIG inhibited polarized microglia activation and attenuated inflammasome-mediated production of proinflammatory cytokines in BV2 microglia cells induced by LPS/IFN-γ and in the brains of 2VO rats. To further elucidate the role of CIG in microglia-mediated inflammatory response, we investigated the expression and activity of calpain. CIG inhibited the expression and activity of calpain 1/2, which was characterized by decreased calpastatin and spectrin αII expression. In particular, intra- and extracellular calpain 1 levels were reduced by CIG. However, CIG showed weak interaction with calpain 1. In addition, we found that CG administration significantly repressed the assembly of the NOD-like receptor protein 3 (NLRP3) inflammasome, including NLRP3, ASC, and caspase-1. In conclusion, our knowledge of the mechanisms by which CIG regulates NLRP3/calpain signaling to influence inflammatory responses offers further insights into potential therapeutic strategies to treat VaD.

Amarogentin has protective effects against sepsis-induced brain injury via modulating the AMPK/SIRT1/NF-κB pathway.

Amarogentin (AMA), a secoiridoid glycoside that is mainly derived from SwertiaandGentiana roots, has been confirmed to exhibit antioxidative, tumor-suppressive and anti-diabetic properties. This research intends to investigate the protective effect of AMA against sepsis-induced brain injury and its mechanism. NSC-34 and HT22 cells were treated with lipopolysaccharide (LPS) to induce an in-vitro sepsis model and then treated with varying concentrations (1, 5, 10 µM) of AMA. Cell proliferation and apoptosis were evaluated. The intensity of inflammation and oxidative stress were assessed by different methods. The AMPK/SIRT1/NF-κB pathway expression was determined by WB. An in-vitro sepsis model was set up with cecal ligation and puncture (CLP) in adult C57/BL6J mice, and different concentrations (25, 50, 100 mg/kg) of AMA were applied for treatment. Neurological function was evaluated using the modified neurological severity scores (mNSS), and the brain tissue damage was measured using hematoxylin-eosin (H&E) staining and Nissl staining. Tissue apoptosis was tested using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. Then, the AMPK inhibitor Compound C (CC) was administered to confirm AMA-mediated mechanism. Our finding illustrated that AMA mitigated LPS-induced neuronal damage, inflammation and oxidative stress, activated the AMPK/SIRT1 pathway and choked NF-κB phosphorylation. Furthermore, AMA improved neurological functions of sepsis mice by reliving neuroinflammation and oxidative stress. Inhibition of AMPK attenuated the protective effect of AMA on neurons or the mice's brain tissues. In conclusion, AMA protected against sepsis-induced brain injury by modulating the AMPK/SIRT1/NF-κB pathway.

Stability of valeriana-type iridoid glycosides from rhizomes of Nardostachys jatamansi and their protection against H2O2-induced oxidative stress in SH-SY5Y cells.

Nardostachys jatamansi is close to Valerian in consideration of their same psychoactive effects, such as sedation and neuroprotection. Valeriana-type iridoids are major active components of Valerian, but few valeriana-type iridoids have been isolated from N. jatamansi. Iridoid-targeting chemical investigation of the rhizomes of N. jatamansi resulted in the isolation of seven valeriana-type iridoid glycosides, four of which are previously undescribed. Their structures were determined through NMR spectroscopy, high-resolution mass spectrometry, and optical rotation experiments. In addition, the inaccurate configurations of patrinalloside and 6″-acetylpatrinalloside from previous reports were corrected. These compounds, unstable due to alcoholic solvents, were more stable in the mixtures than in purified forms, as monitored by the qNMR method, supporting the use of natural products as mixtures. Furthermore, the isolates, as well as crude and solvent partition extracts, were found to have a protective effect against hydrogen-peroxide-induced toxicity in human neuroblastoma cells, as confirmed by assays for cell viability and antioxidation. These findings suggest the potential therapeutic application of the valeriana-type iridoid glycosides isolated herein with improved biochemical stability.

Iridoid Glycosides Isolated from Bellardia trixago Identified as Inhibitors of Orobanche cumana Radicle Growth.

Orobanche cumana is an obligate holoparasitic plant with noxious effects in sunflower crops. Bellardia trixago is a facultative hemiparasitic plant that infects ruderal plants without noxious significance in agriculture and is known to produce a wide spectrum of bioactive metabolites. The objective of this study was to evaluate the allelopathic effects of B. trixago on the growth of O. cumana seedlings. Three different extracts using solvents of increasing polarity (n-hexane, dichloromethane and ethyl acetate) were prepared from the flowers, aerial green organs and roots of two populations, a white-flowered and a yellow-flowered population of B. trixago, both collected in southern Spain. Each extract was studied using allelopathic screenings on O. cumana which resulted in the identification of allelopathic activity of the ethyl acetate extracts against Orobanche radicles. Five iridoid glycosides were isolated together with benzoic acid from the ethyl acetate extract of aerial green organs by bio-guided purification. These compounds were identified as bartsioside, melampyroside, mussaenoside, gardoside methyl ester and aucubin. Among them, melampyroside was found to be the most abundant constituent in the extract (44.3% w/w), as well as the most phytotoxic iridoid on O. cumana radicle, showing a 72.6% inhibition of radicle growth. This activity of melampyroside was significantly high when compared with the inhibitory activity of benzoic acid (25.9%), a phenolic acid with known allelopathic activity against weeds. The ecotoxicological profile of melampyroside was evaluated using organisms representing different trophic levels of the aquatic and terrestrial ecosystems, namely producers (green freshwater algae Raphidocelis subcapitata and macrophyte Lepidium sativum), consumers (water flea Daphnia magna and nematode Caenorhabditis elegans) and decomposers (bacterium Aliivibrio fischeri). The ecotoxicity of melampyroside differed significantly depending on the test organism showing the highest toxicity to daphnia, nematodes and bacteria, and a lower toxicity to algae and macrophytes. The findings of the present study may provide useful information for the generation of green alternatives to synthetic herbicides for the control of O. cumana.